Means for supporting resistor coils in electric furnaces



Aug. 22, 1933.

D. F. CAMPBELL 1,924,079 MEANS FOR SUPPORTING RESISTOR COILS IN ELECTRIC FURNACES Filed April 29, 1931 4 Sheets-Sheet 1 I I 'q i I i 1933 D. F. CAMPBELL ,079

MEANS FOR SUPPORTING RESISTOR COILS IN ELECTRIC FURNACES Filed April 29, 1931 4 Sheets-Sheet 2 Aug. 22, 1933. D. F. CAMPBELL 1,924,079

MEANS FOR SUPPORTING RES ISTOR COILS IN ELECTRIC FURNACES Filed April 29, 1931 4 Sheets-Sheet 3 Aug. 22, 1933. D. F. CAMPBELL MEANS FOR SUPPORTING RESISTOR COILS IN ELECTRIC FURNACES 4 Sheets-Sheet Filed April 29, 1931 Patented Aug. 22, 1933 labl ul v MEANS Fort IN ELECTRIC FU1tNl\(3ES Donald Fraser Campbell, London,

signor to Ajax Electric Company,

delphia, Pa.

Application and in Inc.,

9 Claims. (Cl- 13-25) The invention relates to means for supporting resistance coils in the side walls, roof, floor or doors of electric furnaces, etc., more especially in furnaces in which large spirals of heavy gauge wire are to be inserted or supported.

In the usual known arrangements the contact between the wire and the firebrick impedes the free circulation of air, with the result that-the temperature of the wire is considerably raised at this part.

According to the invention, the brickwork is so formed that each spire of a coil is supported at two points, the col being in contact with the brickwork alongtwo lines, openings provided in the brickwork allowing a free circulation of air at the parts where the resistors are placed.

Means are also provided to prevent currents of heated air from ascending directly to the roof of the furnace.

The invention is illustrated in the accompanying drawings inwhich:

Fig. 1 is an end elevation and Fig. 2 a plan of the supporting brick in the side wall.

Fig. 3 is a section on and Fig. 4 is a plan roof brick.

Fig. 5 is a sectional elevation of the brickwork supporting the coils provided in the floor of the furnace.

Fig. 6 is a section on and Fig. 7 is a plan view, seen from below, of a roof brick.

Figure 8 is a transverse sectional view of a furnace wall constructed according to my invention and taken on the line 8-8 of Figure 9.

Figure 9 is a longitudinal section taken on the line 99 of Figure 8.

Figure 10 is a view similar to Figure 9 but showing a different bond arrangement.

Referring to Figs. 1 and 2,18. represents a brick of a side wall of the furnace, a the inwardly projecting endof the brick, B a spire of the resistor coil.

The part a is-shaped, as shown, so that each spire B is supported at two pointed, a and a free access of hot gases is provided by the openings a Owing to the g for the roof to become hotter than the floor, the following improvement in the usual sidewall brick arrangement is made: 55 If the bricks were placed the line 3-3 of Fig. 4,

view, seen from below, of a the line 1--1 of Fig. '7

one on top of the natural tendency in any furnace other with ordinary half sult would be, a number chimneys conveying a large to the roof of the furnace. of a A brick, the

the solid portion baflle to the hot SUPPORTING RESISTOR COILS England, as-

Phila- April 29, 1931, Serial no. 533,111,

Great Britain May brick bonding, the rcof vertical channels or amount of hot gases By adopting a bond bricks are-so arranged, that brick always acts as. a

through the aperin one gases rising tures in the brick immediately under it, and

ensures a more uniform heatin chamber.

In Figs. 3 and with holes (not of the furnace 4 the roof brick c is provided shown) in which the resistor coils B are inserted and make line contacts at intervals with the projections 0', c.

In Fig.

5 the resistor coils line contacts with the bevelled edges d,

B similarly make 7 d of adjacent floor bricks B.

Air can circulate freely the resistors; these spaces ceiving any scale, which can out or'other means.

by blowing in the spaces d below also serving for rebe easily removed 7 In the modification of the roof brick shown in Figs. 6 and '7, the resistors are supported on a" continuous line contact,

side resistors.

In Figures 8 an as in the hearth and 9, I have shown a furnaceside wall constructed with bricks A which are provided with spire supporting points a anda upon a bracket ,part a.

I have adopted one-j liarter brick bonding in Figures 8 and 9 to cause bracket ato rest d ectly above in the brick below, be defiected in their large amount of hot gases the roof of the furnace.

prevent a directly to While vertical preferable, I find the solid portion of the the opening a I to allow the rising gases to upw'ard travel. This will from'rising staggering of the opening is that desirable circulation may be obtained in the one-half brickbonding ar- I claim:-

rangement shown in Figure 10 in which the apertures a are directly in line,

1. In a wall construction for electric heating furnaces, of the resistor having supporting br ckets horizontally in line t luralit of brick Yp D y with each other to form supports and apertured within the brackets, in combination with resistor spires extending the brick lying over with the engagement transversely with respect to the apertures and having brick above the apertures the apertures.

electric heatin furnaces of the resistor type, a plurality of brick having each a wall portion and a bracket portion no which latter is apertured and oflers engaging surfaces adjacent the aperture and on opposite sides thereof and a resistor spire larger in diameter' than the spacing between the contact points, resting upon them and permitting flow of hot .furnace gases through the apertures and through the spires in line with the apertures to facilitate hot gas circulation.

3. -A heating and hot air circulating arrangement for a wall of an electric heating furnace of the resistor type, comprising a plurality of brick each having a wall portion and an outwardly and upwardly apertured bracket member, the bricks being arranged in superposed rows so that furnace gases passing through the aperture of one bracket can pass through the aperture of the adjoining bracket, in combination with resistor spires supported by the bricks above the apertures, whereby furnace gases heated by one spire can pass through the apertures to the spire above while gas is supplied from below the first spire through the apertures of the brackets upon which it rests.

4. A resistor spire in combination with a bracket supporting the spire at a plurality of points, apertured beneath the spire and outwardly and upwardly directed so that in combination with other brackets it forms a shelf.

a second spire above the first and a bracket supporting the second spire aperture beneath the spire and with other brackets forming a second shelf, whereby the spire of each shelf is fed with furnace gases from the space above the shelf which lies below it and the furnace gases heated by each spire can divide outwardly and upwardly between shelves in one direction and upwardly through the apertures in another.

5. A side wall shelf, a plurality of brackets outwardly and upwardly extending, apertured, and each engaging the next bracket to form a continuous shelf in combination with bricks which are integral with the respective brackets and supporting them, and a resistor spire resting upon the shelf above the apertures and heating furnace gases passing upwardly through the apertures.

6. A plurality of brick or tile each having a body portion for wall position, and an intermediately upwardly and outwardly grooved, upwardly apertured, and upwardly and outwardly projecting bracket member forming a resistor support in combination with a plurality of brick or tile above the first plurality and having the apertures of the one plurality staggered with respect to those of the other.

7. An electric furnace wall brick or tile comprising abody portion adapted to form part of the body of a, vertical wall and a grooved portion projecting into the furnace and having a vertical opening and supporting walls adjacent to the opening and a spire resistor resting on the supporting walls.

8. A furnace brick comprising a body portion adapted to be built into a furnace side wall and a resistor-supporting bracket integral therewith, projecting outwardly and upwardly, apertured, and having resistor supports adjacent to and above the aperture to hold the resistor away from the aperture.

9. A furnace brick comprising a body portion adapted to be built into a furnace side wall and a resistor supporting bracket integral therewith,

projecting outwardly and upwardly, apertured,

and having resistor supports adjacent to the aperture and above the aperture to hold the resistor away from the aperture, in combination with a spiral resistor-permitting movement of furnace gases which pass through the aperture to passtransversely through the resistor.

DONALD FRASER CAMPBELL. 

